Pentair FNS Plus 48 DE Filter - EC-180008



Model # EC-180008

By Pentair Pool Products

  4.78 Average  



Model # EC-180008

Warranty Ecommerce (EC) products: Products purchased from an Authorized Pentair Online Reseller (products beginning with EC-) receive a one (1) year (parts only) warranty from the date of purchase. The exceptions are: IntelliChlor cells and IntelliFlo SVRS pumps which receive a two (2) year warranty. EC products are not eligible for the bundled three (3) year extended warranty.

Alternate Part #'s 180008, EC180008, PENEC-180008

Product Description

Inyo Recommended Filters

Pentair FNS Plus filters are fiberglass reinforced polypropylene of advanced chemical resistant materials for superior strength and reliability. The top manifold design features the Service-Ease grid pack for convenient one-at-a-time grid servicing. Pentiar Backwash valves are sold separately.

  • Superior strength
  • Service-Ease grid pack
  • Continuous High Flow internal air relief*
  • 100% factory tested
  • Top-to-bottom backwash
  • High Flow manual air relief valve
  • Tension Control clamp
  • Black valves and plumbing
  • 1 1/2 in. bottom clean out port
  • 7 1/2 in. centerline bulkhead fittings
  • Warranty 3 Yrs. Shell, 1 Yrs. Parts

Click here for more Pentair Filter

Product Specifications

Multiport Valve:
Filtration Area:
48 sq. ft.
Flow Rating:
96 GPM
Turnover 8 Hrs.:
46080 gal.
Turnover 10 Hrs.:
57600 gal.
Turnover 12 Hrs.:
69120 gal.
DE Required:
4.8 lbs.

?     Asked on 11/15/2022by GARY DALE WILSON

Is this filter free standing or does it require a stand? Which backwash valve will I need? Thank you.

A  Answered on 11/15/2022 by InyoPools Product Specialist Hector F.

Hello Gary, this is filter is free standing and please click here to view the Pentair FNS Plus D.E. Filter parts diagram for this filter series. Key number 32 has all the compatible multiport valves you can use with this filter. 

?     Asked on 11/5/2022by Dennis Armstrong

this comes complete with the grid guts?

A  Answered on 11/6/2022 by InyoPools Product Specialist Hector F.

Hello Dennis, yes this filter comes complete with the grid assembly as well. Please be advised that the multiport valve needed is not included. Please click here to be directed to the parts diagram where the few valve options are listed in case you need one. I have also emailed you an estimate for the filter if you just need to order that. They are in stock and ready to ship. 

?     Asked on 7/8/2021by Dean DuBal

My Pentair 180008 FNS Plus Filter has a hairline crack on the side about midway. Is there a plastic or rubber liner that can be placed inside to stop the leak, or do I have to replace the unit for $1000.00 +/- Thank you, Dean

A  Answered on 7/8/2021 by InyoPools Product Specialist Stephen B.

Thank you for contacting Inyo Pools, Unfortunately,There is nothing you can do that with. If you search the Inyo website with the number you provided you may be able to purchase the top or bottom piece you may need. Pentair FNS Plus D.E. Filter parts page

?     Asked on 4/14/2021by Trey

is this filter in stock and available for immediate shipping?

A  Answered on 4/23/2021 by InyoPools Product Specialist Robert M.

This filter is not currently in stock. We recommend looking at the Waterway Crystal Water 48 DE Filter. That filter is in stock and ready to ship.

?     Asked on 7/2/2020by Ricardo Solis

How much DE used for a Pentair 48 gal. regular monthly backwash?

A  Answered on 11/20/2020 by InyoPools Product Specialist Hector F.

Hi Ricardo, you will want to use approximately 4lbs of D.E. powder after a backwash cycle. 

?     Asked on 6/30/2020by rocco p picerno jr


A  Answered on 10/22/2020 by InyoPools Product Specialist Hector F.

Hello Rocco, this filter is currently in stock and ready to ship. The approximate lead time for delivery is 3-7 business days. 

?     Asked on 6/26/2020by Diego Weiss

Hi, I just need the inside panels,


A  Answered on 11/10/2020 by InyoPools Product Specialist Hector F.

Hi Diego. could you send us a few photos of the complete filter body and of the filter label itself? To supply photos simply click the reply link below and upload your photos. Once we get those photos we can make the proper recommendation.

?     Asked on 5/28/2020by Andrew Acevedo

Hello; I just need the top half of the tank of the FNS PN 180008. is it available, or do I have to purchase the entre system.

A  Answered on 5/28/2020 by InyoPools Product Specialist Hector F.

Yes, the part number for the Pentair FNS Plus filter lid is 4600-0021 that you can view by clicking here. It is available. 

?     Asked on 5/21/2020by lizz

do you carry the backwash valve for this unit?

A  Answered on 5/22/2020 by InyoPools Product Specialist Hector F.

Yes we do. Please scroll down towards the bottom of this parts diagram that you can view by clicking here to view your options. 

?     Asked on 11/25/2019by Inyo Visitor

I have an old Purex triton Nautilus FNS 48 with a crack in the housing. Would the Pentair 180008 FNS Plus be a straight replacement?


A  Answered on 11/26/2019 by InyoPools Product Specialist Lennox H.

Hi. This FNS Plus 48 sqft D.E. Filter is a suitable replacement, however, it's not a drop-in replacement. The valve plumbing connections will have to be lowered by 1" or raise this filter by 1". 

?     Asked on 11/24/2019by Thierry Saint Loup

I have a Pentair FNS Plus 48, PN 190029 Rev D that has a crack below the unit split line and is leaking (my couple of attempt to seal it from inside and outside did not work...) I don't see that reference listed in your website: what is the direct replacement for the whole unit (top and bottom assembly)? Thank you


A  Answered on 11/25/2019 by InyoPools Product Specialist Lennox H.

Hi, Thierry. This FNS Plus 48 - 180008 is the direct replacement for the unit you have. 

?     Asked on 10/7/2019by Scott Deathridge

does this filter come with all of the fittings ready to attach a multiport valve?

A  Answered on 10/8/2019 by InyoPools Product Specialist Hector F.

These filters have the bulkhead fittings on them already however do not come with the backwash valves. 

?     Asked on 8/12/2019by Lee Pavlock

I live in Orlando. Can I pick up an FNS Plus 48 ft DE Filter 180008. Is the price different if I do?

A  Answered on 8/12/2019 by InyoPools Product Specialist Jessica C.

Hi, Lee. Unfortunately, we do not have a retail location that is open to the public. I apologize for the inconvenience. 

?     Asked on 8/7/2019by E. Kyle Steinhauser

Probably a stupid question, but I want to make sure I order the right filter. The P/N on my filter is 180008, and it is a Pentair FNS Plus, FLT FNS PLS. Is this the exact match?


A  Answered on 8/7/2019 by InyoPools Product Specialist Lennox H.

Hi, E. Kyle. This FNS Plus 48 - 180008 is a direct replacement. 

?     Asked on 6/27/2019by Tom

I have a old stainless American titan DE 48 sq ft filter I want to replace. It seems the FNS Plus 48 Sq Ft Filter w/o Valve - 180008 is a direct replacement that will connect up to the multiport valve that's there already. Is that correct? Thanks

A  Answered on 6/27/2019 by InyoPools Product Specialist Lennox H.

Hi, Tom. This FNS Plus 48 Sq Ft Filter - 180008 will not be a drop-in replacement to the American Products Titan Stainless Steel D.E. Filter. The valves are not interchangeable.  

?     Asked on 6/14/2019by Kurt

I have an FNS 48 DE Filter and after cleaning the filter elements I noticed a small leak that I thought was one the unions. I ordered a union wrench to tighten and after tightening the leak seems to be the output flange from the unit, Can that be repaired?

A  Answered on 6/14/2019 by InyoPools Product Specialist Lennox H.

Hi, Kurt. You can try replacing the Bulkhead O-rings and or the Bulkhead Assembly to repair the leak. 

?     Asked on 11/18/2018by Inyo Visitor

I have purex triton nautilus fns48 filter, is the 180008 a direct replacement? Looks like the plumbing on my filter is 7 1/2" center to center not sure of the size. What else would I need to replace? My backwash valve is leaking out the top is it rebuildable? Would rather not redo the plumbing.

A  Answered on 11/29/2018 by InyoPools Product Specialist Lennox H.

Hi. Yes, this FNS Plus is a direct replacement even though the plumbing ports are about 1" lower than the Nautilus FNS 48 model. You can rebuild and reuse your existing valve or replace it. 

?     Asked on 11/6/2018by KERN R PEGUES

I have a Pentair 180008 FNS Plus Fiberglass FNSP48 D.E. Pool Filter that leaking. Can I use the old valve for a new one?

A  Answered on 11/6/2018 by InyoPools Product Specialist Hector F.

Yes, as long as the model number from your old and new one match then you can use the same valve. 

?     Asked on 6/11/2018by Richard

I am getting ready to replace my older FNS Plus 36 which has served me well. I am having an occasional low flow problem with my new HP 140K BTU heat pump showing a "HP" error message which indicates not enough flow for the HP compressor to come on. My question is if I replace my existing FNS 36 with a FNS 48 which shows a higher flow rating, will I get a higher flow rate through my system piping and heat pump without upgrading my existing pump/motor?

A  Answered on 6/11/2018 by InyoPools Product Specialist Lennox H.

Hi, Richard. You will not get a higher flow rate through your system, you will get a longer run time before having to clean or backwash your filter. 

?     Asked on 5/31/2018by Joe Horan

I assume I would need a new multiport valve, also filter is about 6 ft. above pool level' Does the filter have backwash capability ?

A  Answered on 5/31/2018 by InyoPools Product Specialist Lennox H.

Hi, Joe. You will need a valve to operate this filter. With the correct valve, you will be able to backwash the filter. 

?     Asked on 5/31/2018by Jeremy Al Rampy

If I purchase this filter, does it come with a set of grids, or do I need to purchase the grids as well?

A  Answered on 5/31/2018 by InyoPools Product Specialist Hector F.

Yes, this filter comes with all of the grids. 

?     Asked on 4/19/2018by Viki

Can the process of installing the new filter can be be a DIY project?

A  Answered on 4/19/2018 by InyoPools Product Specialist Michelle B.

Hello, Here is a great DIY article on how to install a DE filter.

?     Asked on 7/5/2017by MJ

what multiport valve will go with de backwash filter 180008 FNSP48

A  Answered on 7/6/2017 by InyoPools Product Specialist Lennox H.

Hi, MJ. A list of compatible MPV are available on the Pentair FNS Plus D.E. Filter parts page. 

?     Asked on 6/21/2017by Inyo Visitor

What is the grid size I need for this filter? Item number? I believe I need 7 full and a 1/2 one for a total of eight.

A  Answered on 6/21/2017 by InyoPools Product Specialist Patrick P.

For the FNS Plus 48 you will require this FNS Plus 48 DE Grid Pack the pack includes the 7 full grids and the 1 smaller partial grid.

?     Asked on 5/28/2017by chris

I just need the band to go around this. and a new pressure gage. what are the parts numbers and how do I get these items?

A  Answered on 5/28/2017 by InyoPools Product Specialist Patrick P.

Hi Chris, Here is the Band Clamp Assembly for the FNS Plus DE Filter and here is the FNS Plus Pressure Gauge.

?     Asked on 2/27/2017by Inyo Visitor

Do you offer this with filter in 1-1/2" plumbing? Id rather not have to use a reducer if its 2"

A  Answered on 2/27/2017 by InyoPools Product Specialist Andy O.

Hello- This filter would require a multiport valve to be installed with it. You can use the 1.5" Threaded Multiport Valve for D.E Filters - 261177 instead of using the 2" valve.

?     Asked on 1/13/2017by Tom

Should I use a 36 Square ft triton FNS or a 48 square ft pool is approx. 200000 gallon with one HP Pump

A  Answered on 1/16/2017 by InyoPools Product Specialist Adam Y.

Good morning Tom, I would go with the FNS Plus 48 Sq Ft Filter w/o Valve - 180008

?     Asked on 9/3/2016by Inyo Visitor

I found the filter but can the shell be bought separately?

A  Answered on 9/8/2016 by InyoPools Product Specialist Scott W.

The top and bottom tank are sold separately. Part numbers 4600-0017 and 4600-0021.

?     Asked on 7/19/2015by PG

I have a Pentair Filter Part # 180008 on the bottom of the tank is a plug that started to leak water i went to check it and it fell off what can I doe to fix this

A  Answered on 7/19/2015 by InyoPools Product Specialist Dennis R.

PG - I think you are referring to the drain plug at the botton of the tank. This plug should screw back in. If the plug's threads are stripped, here is a link the filter's parts list :Drain Plug (#24) and associated O-ring (#23). If the threads in the tank are stripped, you will have to buy a new tank bottom (#25) or a new filter.

?     Asked on 6/23/2015by bob feeney

I have a 30 year old sylvan pool with 48 KDI de stainless filter and 6 way multiport americana valve. Please advise on filter and valve selection.

A  Answered on 6/24/2015 by InyoPools Product Specialist Lennox H.

Hi Bob, You can go with the Pentair FNS Plus 48 Sq Ft Filter w/o Valve and you can use the 1.5" Threaded Multiport Valve for D.E Filters or the 2" Multiport Valve Threaded for D.E depending on your size plumbing.

?     Asked on 7/23/2012by Guest

I have a 27 year old 20x40x4 pool with a 1.5 hp Hayward Super Pump and an Lomart DE Filter that developed a slow leak I can't stop. Replacement parts no longer available. There are 30 ft of 1.5 inch tubing from the skimmer to the pump and 20 ft of 1.5 in return line. Pump is at pool water level. The old Lomart has 9 D.E. disk filters with a total surface area of 25 Sq. Ft. I am looking for an over sized D.E. filter replacement. Is the Pentair 180008 one of the better replacements? Can you sugge

A  Answered on 7/23/2012 by InyoPools Product Specialist Patrick P.

Yes this Pentair filter would be a great replacement and considerable upgrade from you Lomart filter. If you go with this Pentair filter then you would also need to purchase the Pentair 1.5" mulitport valve. Thanks for the great question.


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 (Average 4.78  out of 5 stars)
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